Evaporative cooling system



Nov. 24, 1959 M. BURGEss `EvAPoRATIvE COOLING SYSTEM Filed Jan. 3, 1 956INVENTOR s x 3 6p Wand. M Q 5 f Z, v.4 B

United States Patent ''cooiiv"G SYSTEM Leslie M.v Burgess; Burbank,Calif. Application January '3f956gseriaNu 356,880 11 claims; (c1-.162mmThis invention relates to evaporativeeoolingsysterns for precoolingarticles of produce and 'the like priorto shipment and particularly to'a metho'dand apparatus for this purpose utilizing a liquidspr'aycondensing medium.

The evaporative cooling process `is"`wel1` understoodin the art andinvolves the pl'cing of thefarticles 'to 'b'e cooled in a sealedchamber, evacuation Vof die chamber to` an absolute pressure equal to orslightly less than `th"e vapor pressure of the surface moisture on thearticlest'o cause such moisture toevapora'te and Vboil off, Withresultant cooling of the articles, land removal of tlie Water vapor orsteam as it is formed so as to maintain the vapor pressure in thechamber sbstantiallybelov thesaturated :vapor pressure of thesur-face'moisture, or ice', t its then temperature. l p

A primary object of this invention ifs the provision :of an improvedmethod and 'apparatus for such"`evap'orative precooling of articles ofproduce and the` like.

Various systems have beenprop'osed for 'effeetively'r'fenoving the largevolumes of vapor evolved' during the cooling process so as to maintainthe latter-process 'atan optimum rate.

precooling of articles of produce or the like'ivnvolvinig the use of aliquid 'spray astheeondensiiig medium.

One general form of spray-type condensing system `utilizes a containerwhich is initially filled with the condensing liquid, the latter being`maintained at a low temperature by the immersion of ice or coolingycoils therein. During operation of the system, the cold liquidisvvithdrawn from the container and sprayed into a condensing chamberfor contact with theevolvd vapor. The condensed vapor and condensingliquid become inter- 4mixed and areA collected in a suitablereservoir'from which they are discharged to a waste facility.`While'spray-type condensing systems of -this character possess the'advantage of enabling the condensing liquid to be effectivelymaintained at the required-W temperature necessary for rapid andeflicient condensing of the relatively low temperature vapor evolvedduring the -latter `stages of the cooling process,` they are deficientin that in evaporative cooling apparatus of any substantial capacity,the initial supply of condensing 'liquid Vmust be `of considerablevolume to provide suicient condensing uid'for the entire"cooling'process p Such large volume of` condensing liquid, obviously,results inacooling plant of substantial lfriagnitude and one which issuitable for onlyY permanent 4 installations.

To avoid this deficiency, spray-type condensing systems have beenproposed wherein a relative1y"smallvolume of 'condensing liquid iscontinuouslyfrecircultedthrough the -4System. This recirculationlof the"condensing liquid, "s

will V be-apparent, requires continuous recooling thereof, after itsContact with 'the vapor, to *the 10Wv temperature necessary to efcientland rapid condensation of the vapor.

Moreover, since rapid and ecient condensation of the evolved vapor ispromoted by a high velocity spray, `providing for more eicient heattransfer between the vapor and condensing liquid droplets and more rapidmovement of the heated droplets and condensed vapor from the condensingzone, the condensing" liquid must be recirculated at a rapid ratethrough the system. Accordingly, cooling of the recirculating condensingliquid must be rapidly and eiciently accomplished.

Existing spray-type condensing. systems of this latter nature generallyaccomplish `the recooling of the Vcondensing liquid by recirculating itthrough a tank containing cooling coils. Efficient recooling of thecondensing liquid is not thereby obtained since only a small `portion ofthe liquid in the -tank will `Contact the coils, and the relativelyslovv movement of the condensing liquid over the coils results in the`creation lof astagnant, insulating `layer of liquid about the coilsurfaces which substantially impedes the transfer of heat from the main-body of the liquid to the coils. p i' A further object of thisinvention is therefore the provision of a method and apparatus forevaporative precooling yof articles of `produce and the like utilizing arecirculating liquid spraytype condensingmedium and `wherein recoolingofthe reirculating liquid condensing fluid is more rapidly andeffectively `accomplished than heretofore possible. Y p

Still 'a further object of the invention is the provision of a methodand apparatus of the class described which employs chopped ice as theagent for recooling the liquid condensing fluid, andwhereinheat transferfrom the condensing liquid to the recooling agent is rapidly andeffectively accomplished by impinging the spray of the liquid condensingmedium directly on theparticles of chopped ice.- a Yet a further objectof `the invention is the provision of an evaporative cooling method andapparatus wherein chilled condensate -maybe returned tothe produce afterchilling of the latter for rehydrating purposes.

Alstill further o bject is Ythe provision of vacuum cooling apparatus ofthe class described which embodies a novel meansof loading ice, forrecooling the liquid condenser, into the system.

And a further obect is the provision of an evaporative cooling methodand apparatus'of the class described which is-adapted to a`semi-portable installation, relatively inexpensive to use andmanufacture, and which-possesses a substantially reduced cooling period.

These and other objects -of the invention are accom- Aplished by`evacuating Ithe cooling chamber, containing ythe articles to be cooled,to cause the surface moisture on such articlesto evaporate and boil offwith resultant chilling of the articles. The aqueous vapor evolvedduring the cooling process is contacted with a high velocity spray o frecirculated, cold, condensing liquid whereupon the Vevolved vaporcondenses and intermixes with the condensing liquid. The high velocityspray, consisting nowof droplets, of condensing liquid and condensedvarpor droplets, is `impinged directly `on the surfaces of particles ofchopped ice, for recooling of the condensing liquid. The recooled liquidand condensed vapor are then returned to the spray nozzles forrepetition of the cycle. The high velocity of the spray effects intimate'contact of the liquid therein with the surfaces ofthe chopped iceparticles, which tend to float at the surface of the more dense liquid,lsov'as to provide for rapid and effective heat-transfer fromthe liquidto the ice. Also, constant agitation of tlrebo'dy'of` liquid and'fthechopped ice particles by 'the'spray further" promotes cooling of theliquid and inhibits fusing of the particles together. ing of theparticles is, of course, undesirable since it results in a reduction ofthe effective heat transfer surface area of the ice.

The preferred and illustrative embodiment of the present apparatusincludes a novel means for loading ice into the apparatus prior to itsoperation.

The preferred embodiment of the invention also includes means forreturning cooled liquid from the condensing chamber to the articlesbeing cooled at the termination of the cooling process for coolingprocess for rehydrating of the articles.

A better understanding of the invention may be had from the followingdetailed description and .attached drawings wherein:

Figure l is a schematic illustration of the present vacuum coolingapparatus;

Figure 2 is a section taken along line 2-2 of Figure l; and

Figure 3 is a view schematically illustrating a modiiied form of thepresent apparatus.

Referring now to Figures l and 2 of the drawings, the present vacuumcooling apparatus illustrated therein comprises a hollow, cylindricalretort integrally closed at one end by an end wall 12 and closed at theother end by a hinged door 14 which may be releasably locked in itssolid line, closed position, wherein it seals the open end of the retort10, by means of suitable holding devices 16. Door 14 is movable to itsdotted line, open position to permit the introduction of a load ofproduce 18 or other articles to be chilled into the interior of theretort. Tracks 20 may be secured to the lower portion of the interiorwall of the retort, as illustrated, for supporting a wheeled platform 22on which the produce may be loaded.

The interior of the retort 10 is separated, by a partition 24 ofsuitable heat insulating material, into a pair of chambers 26 and 28,the former of which forms the cooling chamber and the latter of whichforms the condensing chamber of the present evaporative coolingapparatus. The upper edge of the insulating wall 24 terminates somewhatshort of the upper portion of the inner cylindrical wall of the retortso as to provide a space through which vapor may flow from the cooling'chamber 26 to the condensing chamber 28, as Will presently be morefully described.

Mounted in the upper portion of the condensing chamber 28 are a seriesof headers 30 each mounting along their length a plurality of downwardlydirected spray nozzles 32. The headers 30 are connected through a uidconduit 34 to the discharge side of a pump 36, the intake of which iscommunicated via a fluid conduit 38 to the bottom of the condensingchamber 28. Line 34 includes a three-way valve 40 having one positionwhereon the headers 30 are connected to the discharge of pump 36, asecond position wherein the headers are connected to a line 41 leadingto a supply, not shown, of condensing liquid for initially charging ofthe system, and a third closed position.

Evacuation of the cooling chamber 26 and condensing chamber 28 toprovide for the initial evaporation and boiling off of the surfacemoisture on the articles to be cooled is accomplished by a vacuumproducing means 42 having its intake side connected to the upper portionof the condensing chamber 28, on the end thereof remote from the coolingchambers 26, by a line 44, the lower ends of the discharge nozzle 32being disposed somewhat above the plane of the opening of the conduit 44into the condensing chamber 28, as shown. A bathe 45 is disposed betweenthe nozzles and open end of conduit 44, as shown.

In use of the present apparatus, as will be presently more fullydescribed, the condensing chamber 28 is initially filled with Water W,or other condensing liquid having a speciiic gravity greater than ice,from line 41 by Fusoperation of valve 40 to said second position, to alevel,

designated as L1. Means 42 is now operated to evacuate the cooling andcondensing chambers 26 and 28, as previously described, and the evolvedwater vapor tlls the cooling chamber 26 and the condensing chamber 28.Valve 40 is turned to its aforesaid rst position, and pump 36 isoperated to draw the condensing liquid W from the bottom of thecondensing chamber 28, through the intake line 38, and discharge itthrough the line 34 to the headers 30 whereupon it issues as a series ofsprays through the discharge nozzles 32. The water vapor, evolved fromthe articles being cooled, comes in contact with the droplets ofcondensing liquid in these sprays and is condensed and intermixed withsuch condensing liquid and falls therewith to the bottom of thecondensing chamber. Substantially all of the water vapor will becondensed in this manner so that the evacuating means 42 is loaded onlyto the extent of removing non-condensible gases. Due to suchcondensation of the water vapor, the pressure in the retort ismaintained at the value necessary to assure boiling off and evaporationof the surface moisture of the articles being cooled, especially duringthe latter stages of the cooling process. The baille 45 prevents thespray issuing from nozzles 32 from being drawn into the means 42 whilepermitting removal of non-condensible gases.

It will be seen that the condensed vapor and initial condensing liquid Ware continuously recirculated by the pump 36 through the spray nozzles32 so that means must be employed for recooling the condensate andcondensing liquid prior to their recirculation to the nozzles 32, to atemperature suiciently low to provide for continuous, rapid andeffective condensation of the vapors.

Recooling of the condensate and condensing liquid, as preliminarilymentioned, is accomplished through the use of chopped ice. To this end,a pair of ice hatches 50 are provided on the top of the retort over thecondensing chamber 28 through which ice may be loaded into the latter.Another method of loading ice into the retort involves a sluicingprocess, and for this purpose there is provided a second line 52,including a valve 54, leading from the discharge side of pump 36, to anozzle 56 which discharges into a hopper 58. Hopper 58 is provided withan opening 60 through which chopped ice from a supply 61 may beintroduced into the hopper. For most etiicient operation of the system,the individual chunks or particles of ice should weigh no more than tenpounds. A discharge conduit 62 leads from the hopper 58, through the endwall 12 of the retort, into the condensing chamber -28 at a point abovethe initial liquid level L1 in the chamber. This conduit includes avalve 64. In operation of the sluicing system, valve 40 in the line 34leading to the spray nozzles 32 is closed and valve 64 in the dischargeconduit 62 from the hopper 58, and valve 54 in line 52 are opened. Pump36 is then operated to pump liquid from the condensing chamber 28through the line 52 to the discharge nozzle 56. Chopped ice isintroduced into the hopper 58 from the supply 61, such ice being forcedinto the condensing chamber 28 by the liquid discharging from the nozzle56. A valve 66 provides for the discharge of pump 36 to a drain conduit68 for draining of excess liquid from condensing chamber 28. This drainconduit may include a meter 69 for indicating the quantity of liquiddrained olf so that a predetermined volume of liquid may be removed fromthe chamber 28 at the termination of each run to return the liquid tothe level L1.

As previously mentioned, it is often desirable to return cooled liquidto the articles of produce after chilling of the latter. To this end athird conduit 70, including a valve 72, leads from the discharge side ofpump 36 to means 74, adjacent the open end of the retort 10, forreturning the condensate to the produce. The means 74 is illustrated asbeing a spray nozzle through which cooled liquid from condensing chamber28 may be dis- `flowing overthe surfacesto the hody of liq imelts, thelevel of the body of liquid' W willoh or water W7 from line 41, tothelevel L1', as previously 'described. The condensing islloa'ded'withchopped ice, either through the hatches.50 or by the previouslydescribed operationlof the, sluicingsystern S6, 8,

61, to a higher level designated bythe'letter L2. Owing tothe lesserdensity of the;ice,2 the ice particles P will tend to rise to and floatatv the surface, of the liquid W.

Means 2 is now operated to `evacuate the cooling'and condensing chambers26 and 28, until thev absolute pressure in such chambers isequal toor`.slightly lessthan the vapor pressure of the surface moisture on thearticles to becooled. Duringthis process,. surfacemoistre will firstevaporate and thenboil off with the'resul'tant formationof atrelativelylargevolume of aqueous vapor which llsthe cooling chamber 26andkrcondensingchalmber 28. Pump 36 is startedgand: thevalving of theapparatus is appropriately positionedso `that liquid drawnfrom thebottom of the condensingcharnbergZV and ,discharged as high velocitysprays 1through tl'iey `noz es 32. lfhe vapor evolved from the articlesbeing chilled is drawn into contact with t h is spray/,becauseio'f thelower vapor pressure of thev spray, and becomes condensed thereon andinterrnixed therewithmThis condensation of the vapor results inmaintenance.,of,fthe vapor pressure in the retort'at a value necessarytomaint'ain evaporation `and boiling off of the lliquid :moisture on thearticles l cooled. The liquid inthesprfay impinges the surfaces of theice particles HP, andisfthereby cooled, such liquid f id W at the bottomof the condensinggzchambenfor Vrecirculation ti the nozzles 32. This:bodyl'ofliquid will, of course, be further lcooled by the ice therein..hf

As the evolved Vapor is condensed, and as ice . v i v t l l t n 1 J riseabove the level L12 The ice particles.Pwill, however,

float in vthe liquid so as to remainV at the surfaceth'ereof L andbeexposed to the spray for continuousimping'enient of thelatter on theicesurfaces. l m A highly important feature oftheinventionresidesin thisdirect impingement of the highV velocity "sprays from nozzles 32 on thesurfaceof the'ice particles P. rlfhe high velocity of the sprayactstobripgpthe ycondensed `vapor and condensingeliq'uid into intimatecontact with the ice surfaces and to 'thoroughly agitate the boidy ofliquid W andthe ice particleslsoasftolamconfplishfmoe rapid andeffective heat transfe fromthe conde nstt'efandY condensing liquid toice `thn is` pos hle `with` systems relying on mere immersionofltherec i'ng agentinfa relatively static body of,conderisi`ng liquid`. Also,`this agitation inhibits fusing togetherof "the icepiarticles whichwould result in ak reductionof the K'effective heat transfer surfaceareaof the ice.` m

An alternative form ofthe vpresent` apparatus, illustrated in Figure 3,comprises'separate coolingandcondensing retorts 100 and 102interconnected lbyaduct 104. The condensing retort 102 includes an icehatch 106, as in the apparatus of Figures 1 and 2. A series oftransversely extendingheaders 112 are positioned within the upperend ofthefcondensing retort and mount a plurality of downwardlydischargingspray nozzles 114. The `headers112are connected by a line 116to the discharge of a pump 118 whose intake isconnected by a line 120 tothe bottom ofithe condensing retort 102. The lcondensing and coolingretorts `a`re evacuated by operation of a vacuum producing device 122`whose intake is connected by a line124 to`,:tlieminterior of thecondensing retort. The appartusiof Figure `3 rf'ngement for loading icein`to`the` condensing "retort,

` means jfor returning the; .cooled condensatel to the uce, a 'n' d thevalving for draining and initiallych'afrging thesysmwith the condensingliquid'W. Theselthave',l `for the: sake of clarity,A been omitted frornFgre 3, i N

Operation ofthe latter forms of apparatus is identical with thatpreviously presented so that no discussion thereof is deemednecessary.Suffice it to say that the hodyof condensing liquid W will be initiallyat a level L1; The cbndensing chamber is loaded with chopped ice to alevel L2.u Thus, as in the case of the apparatus of Figures l and 2, thespray from the nozzles 114 will impinge the surfaces ofthe chopped' iceparticles' P t`o Irovide more eflcient heat transfer between the liquidin the spray and theirecooliiigagent.

While certain preferred embodiments of the invention have been describedand illustrated, it will be apparent that numerous'modications indesign, arrangement'of parts, and procedure are 'possible within thescope'of the following claims.

I claim:

Evaporative cooling apparatus comprising: hermetic chamber meansincluding'a cooling chamber for receiving hydrous articles to` bechilled and a condensing chamber communicating with said coolingchamber;V evacua'ting means communicating with said `condensing chamberfor evacuating the latter and cooling chamber whereby to produce aninff'unjof vapor evolved from articlesin the cooling chamber into thecondensing chamber; saidcondensing chamber defining a condensing zoneadjacent the influir4 of vapor into the condensing'chamber and a'reservoir at one side of said zone; means for recirculating `a in thespray collecting in the reservoir, 4`and means for pumping liquid fromsaid reservoir back` to saidl spray formingrneans; and means forinitially fillingsaid reser- Voir tona'given level with chopped ice tobe viriipinged by the spray, said last mentioned means comprising ahopper adapted to contain chopped ice, a conduit having an unobstructedpassage capable ofpa's'sing the particles o f ice communicating saidhopper and "reseriioir, andia nozzle to be connected to a source offluid under presse and arranged to discharge through said hopper 'intovsaid conduit to force the particles of chopped ice from'the hopper,through the conduit, into said reservoir.

2. The subject matter of claim l including Aconduit means connectingsaid nozzle and pumping means for pumping of liquid from the reservoirthrough said nozzle when filling ther'eservoir with chopped ice, "andvalve means whereby liquid 'may be pumped from the' reservoirselectively to said spray forming' means or nozzle.

3.l In evaporative cooling apparatus of `the class de- 'scribed,'acondensing chamber, means for loading chopped ice into said chamberincluding a hopper adapted to receive a quantity 'of chopped ice;`conduit means connecting said hopper and chamber and having anunobstructed passage therethrough capable of passing the particles ofchopped ice from -the hopper to the chamber; a nozzle arranged todischarge through said hopper into conduit means; and means forsupplying said nozzle with a liquid under pressure.

4. The subject matter of claim 3 wherein said chamber defines areservoir adapted to contain a quantity of a liquid; said last mentionedmeans comprising pump means having its intake connected to saidreservoir and its discharge connected to said nozzle. y

5. Evaporative cooling apparatus comprising: hermetic chamber meansAincluding a lcooling chamber for receiving hydrous articles to bechilled and a condensing chamber communicating with said coolingchamber;

evacuating means communicatingwith said condensing chamber forevacuating the latter and coolingchamber whereby to produce an influx ofvapor evolved from articles in the cooling chamber into the condensingchamber; said condensing chamber defining a condensing zone adjacent theinilux of vapor into the condensing chamber and a reservoir at one sideof said zone; means for recirculating a liquid through said zoneincluding spray forming means at the opposite side of said zone arrangedto discharge a liquid spray into said zone for contact with the vaporentering the condensing chamber, liquid in the spray collecting in saidreservoir, and means for pumping liquid from the reservoir back to thespray forming means; a quantity of chopped ice at said one side of thezone located to be directly impinged by said spray; and means connectedwith said pumping means for selective pumping of liquid from saidreservoir to a desired point outside of said chamber means forrehydrating of said articles after chilling thereof.

6. In evaporative cooling apparatus of the class described, hermeticchamber means having a sealable access opening through which hydrousarticles to be chilled may be loaded into the chamber means, evacuatingmeans for evacuating said chamber means to cause boiling off of thewater content of hydrous articles in the chamber means, condenser meansin the chamber means for condensing the aqueous vapors evolved from thearticles and including nozzle means for creating a water spray throughwhich said vapors pass to be condensed, a reservoir for receiving thespray and the condensed vapors, a conduit leading from said reservoir tosaid nozzle means, a pump in said conduit for pumping liquid from saidreservoir to said nozzle means, a liquid line leading from said conduitat the discharge side of said pump to the outside of said chamber meansthrough which liquid from the reservoir may be' applied to chilledarticles after removal of the latter from the chamber means, and valvemeans for controlling liquid flow through said conduit and line.

7. A method for condensing a condensable gaseous substance comprisingthe steps of: directing a spray of a liquid condensing medium having aspecific gravity greater than ice through a condensing zone into a bodyof said liquid medium having a free surface exposed to said spray andcontaining particles of chopped ice which oat at said free surface ofsaid body whereby said ice particles are impinged and agitated by thespray to promote heat transfer from the liquid medium to the iceparticles and inhibit fusing of the latter, recirculating liqquid fromsaid body through said zone, and passing said substance through saidzone for contact with the droplets of the spray. p

8. An evaporative cooling process comprising the steps of: placinghydrous articles to be chilled in a hermetic space, evacuating saidspace to cause aqueous vapors to be evolved from said articles, passingsaid vapors through a condensing zone in said space, directing a sprayof a liquid condensing medium having a specific gravity greater than icethrough said zone into a body of said liquid medium having a freesurface exposed to said spray and containing particles of chopped icewhich float at said surface of said body whereby said ice particles areimpinged and agitated by the spray to promote heat transfer from theliquid to the ice particles and inhibit fusing of the latter togetherand recirculating liquid from said body through said zone.

9. Evaporative cooling apparatus comprising: hermetic chamber meansincluding a cooling chamber for receiving hydrous articles to be chilledand a condensing chamber communicating with said cooling chamber;evacuating means communicating with said condensing chamber forevacuating the latter and cooling chamber where by to produce an inuX ofvapor evolved from articles in the cooling chamber into the condensingchamber; said condensing chamber defining a condensing zone adjacentyvoir anda higher specific gravity than said ice whereby chopped iceparticles oat'at said free surface; and means for recirculating liquidfrom the reservoir through said zone Yincluding spray forming means atthe top of the zone arranged to direct a high velocity spray of saidliquid through said zone into said reservoir and against the iceparticles floating at said free surface of said liq- Vuid in thereservoir whereby to promote heat transfer from the liquid in the spraytothe ice particles and agitation of the particlesto inhibit fusingthereof together,

'and a pump having its suction communicating with said reservoir belowsaid given level and its discharge communicating with said spray formingmeans, the wall of said condensing chamber having a scalable openingthrough which said` chopped ice may be loaded into said reservoir. i

10. Evaporative cooling apparatus, comprising an elongate, hermeticretort; a liquid tight transverse partition sealed to the inner wall ofsaid retort and defining at opposite sides a cooling chamber and acondensing chamber; said retort having a sealable opening through whichhydrous articles to` be chilled may be loaded into said cooling chamber;a quantity of chopped ice and a condensing liquid filling the lowerportion of said condensing chamber, said liquidfhaving a higher specificgravity than ice and a free surface at a given level in said condensingchamber whereby particles of chopped ice iloat at said free surface ofthe liquid, there being an opening vcommunicating said lchambers abovesaid given level; evacuating means communicating with said condensingchamber above said given level for evacuating saidchambers to produce aninflux of vapor evolved from articles in the cooling chamber into saidcondensing chamberjmeans for recirculating said liquid through thecondensing chamber including nozzle means in said condensing'chamberadjacent said opening, and a pump having its suction communicating withsaid reservoir below said given level and its discharge communieatingwith said nozzle means for pumping said liquid from the lower portion ofthe condensing chamber to said nozzle means, said nozzle means beingarranged to spray said liquid into the path of the vapor entering thecondensing chamber from the cooling chamber and against the particles ofice at said free surface of the liquid in the lower portion of thecondensing chamber to promote heat transfer from the liquid to the iceparticles and agitation of the latter to inhibit fusing thereoftogether, the wall of said condensing chamber having a scalable openingthrough which said chopped ice may be loaded into said reservoir.

1l. In evaporative cooling apparatus of the class described, condensormeans comprising: a hermetic condensing chamber dening a lowerreservoir; a quantity of chopped ice and a condensing liquid in saidreservoir, said liquid having a specific gravity greater than ice and afree surface at a given level in the reservoir whereby particles ofchopped ice float at said free surface of said liquid; and means forrecirculating said liquid through the chamber including spray formingmeans above the reservoir, and a pump having its suction communicatingwith said reservoir below said given level and its dischargecommunicating with said spray forming means for pumping liquid from thereservoir to the spray forming means; said spray forming means beingarranged to spray said liquid toward the reservoir and against theparticles of chopped ice at the free surface of the liquid in thereservoir whereby to promote heat transfer from the liquid to the iceparticles and agitation of the latter to inhibit fusing thereoftogether, the wall of said condensing chamber having a sealable openingthrough 9 which said chopped ice may be loaded into said reservolr.

References Cited in the iIe of this patent UNITED STATES PATENTS1,708,253 Bell Apr. 9, 1924 1,756,992 Quiggle May 6, 1930 2,065,358Zarotschenzeft Dec. 22, 1936

